Relations between Russia and the U.S. have deteriorated as the two countries have struggled to find common ground in Ukraine.

Russian President Vladimir Putin has told Barack Obama in an Independence Day message that he hopes the countries can improve relations.

In a statement published on the Kremlin website on Friday, Putin said “regardless of difficulties and disagreements” he hoped that Russia and the U.S. could “successfully develop relations on pragmatic and equal grounds.”

Relations between Russia and the U.S. have deteriorated as the two countries have struggled to find common ground in Ukraine, where Russia annexed the Black Sea region of Crimea in March and a conflict in the east of the country has claimed over 400 lives.

The United States reacted by imposing sanctions on some of Putin’s associates, and has threatened to take further action.